Latching device



June 6, 1950 C, LOMHOLT 2,510,122

LATCHING DEVICE Filed May 1'7, 1946 afn/f' T ORNEY Patented June 6, 1950 UNITED STATES PTNT CFFICE LATCHING DEVICE Carl Lomhclt, Bogota, N. J., assigner to Federal Telephone and Radio Corporation, New York, N. Y., a corporation of Delaware Application May 17, 1946, Serial No. 670,5d8

(Cl. 'i4-536) 7 Claims.

The present invention relates to latching devices and particularly to latching devices for use in multiposition switching keys such as those commonly used in the telephone art.

More particularly still the device of this invention is designed to be utilized as an attachment for any one of a, large number of specically different switching keys of the telephone type.

It is an object of the invention to provide an improved latching device for switching keys of the lever type or in other words a device for locking a telephone type key lever switch in any one of its plurality of positions.

It is another object of the invention to provide such a latching device which will permit ready operation of the key lever from one position to another and which will hold the key lever positively in any adjusted position.

It is a, further object of the invention to pro-A vide such a key lever latching attachment which may be easily operated with one hand.

It is a still further object of the invention to provide such a latching device which may be readily installed on a key lever switch and which is simply and economically manufactured.

Other objects and features of the invention will appear when the following description is considered in connection with the annexed drawing, in which- Figure i is a central cross sectional view of the latching device of the present invention showing its application to a standard form of telephone switching key;

Figure 2 is an end elevation of the key of Figure l; and

Figure 3 is a top plan view showing the arcuate latching plate which cooperates with the latching device of Figures 1 and 2.

Referring now to Fig. 1, there is shown at i the switch plate of a normal telephone type key lever switch, this plate being mounted on the framework I i which is in turn supported in any suitable manner, as, for example, by internally threaded studs I2 riveted to framework II. The pivoted operating or key lever I3 is pivoted at the point i3d in the usual manner and terminates in a threaded shank I4. In the normal key not supplied with my latching device a handle of any suitable material is threaded on the shank I4.

The latching device of my invention comprises a tubular body member I5 which may be made of metal and which is provided with two downwardly extending latching projections I6. Body member I5 is provided with a rectangular cut-out at I9 which cooperates with the latching plate of Figure 3 in a manner which will be hereinafter described. The exterior diameter of the upper portion ci" the member i5 is reduced and forms a seat for a sleeve I1 of suitable material as, for example, Bakelite. Knob i8 which may also be of Bakelite screws into an internal thread in the upper portion of the body member i5 and thus holds sleeve il in place on its seat. If desirable the sleeve Il and knob S8 may be integral.

The body portion i5 is also recessed as indicated at 2B providing a space in which a coil spring is compressed, the upper portion of the spring 2i resting against the head of an internally threaded sleeve 22 which sleeve is threaded onto the shank It. The exterior surface of sleeve 22 forms a bearing for the interior bore of the body member i5.

Mounted on the switch plate Iii in any suitable manner as, for example, by means of the screws '23 is a member 24 which comprises the upstanding arcuate plates 25 which lie within the cut-out i9 and guide the key lever I3 in its pivotal movement. Each of the arcuate plates 25 has a plurality of latching lugs 26 bent therefrom and lying in generally horizontal planes as seen in the drawing. The latching projections it of the device cooperate with the latching lugs 25 to hold the switch in any position in which it is set.

As will be clear when it is desired to install the device of my invention on a key switch the usual u handle is removed from such switch and the body member i5 slid over the shank i4 of the key lever i3. The spring 2l is next inserted in the recess 2t and the threaded sleeve 22 is then screwed into the shank. Next, sleeve Il is inserted over the exterior of the body member I5 and the knob is screwed into position with its external threads meeting with the internal threads in the body portion I5, thus completing the assemblage and causing the body member and the latching lug carried thereby to be pressed downwardly as seen in the drawing.

When it is desired to operate the switch the sleeve Il or handle I8 is grasped in the ngers and moved upwardly compressing the spring 2l and causing disengagement of the projections I6 of the body member i5 from the lugs 26. Thereupon, the key lever I3 is pivoted about the point I3a to its desired position and the handle then released whereupon spring 2l causes the downward projections i6 to again engage against the lugs 26 to hold the switch lever in its new position.

While I have described a preferred embodiment of my invention it will be understood that 3 other forms may be devised without departing from the scope of the invention and, therefore, l do not desire to be restricted to the particular details shown and described but only within the scope of the appended claims.

What is claimed is:

l. A latching device fer attachment to a key lever switch, said device comprising, in combination, a latching member having arcuate upstanding arms mounted on the switch face plate with said arms extending one on either side of the key lever and parallel to its path of movement, a plurality of latching lugs oneach of said `Lip-standing arm, a body member mounted on the key lever and having a cut-out portion fitting over said upstanding arms, latching projections on said body member for engaging said latching lugs and spring means urging said body member toward said latching lugs and into engagement therewith.

2. A latching device for attachment to a key lever switch, said device comprising, in combination, a latching member having arcuate upstanding arms mounted cn the switch face plate and extending one on either side of the key lever and parallel to its path cf movement, a plurality of latching lugs on each said upstanding arm, a body member mounted on the key leyer and having a cut-out portion fitting over said upstanding arms, latching projections on said body member for engaging said latching lugs, spring means urging said body member toward said latching lugs and into engagement therewith, and a handle member connected to said body member.

3. A latching device ier attachment to a key lever switch, said device comprising, in combination, a latching member having arcuate upstanding arms mounted on the switch face plate and extending one .oneither side of the key lever and parallel to its path of movement, a plurality of latching lugs on each Said upstanding arm, a body member mounted on the key lever and having a out-out portion fitting over said upstanding arms, latching projections on said body member for engaging said latching lugs, spring means urging said body member toward said latching lugs, a sleeve mounted on said body member, and an operating handle fixed to said body member and holding said sleeve in position thereon.

4. A latching device for attachment to a key lever switch comprising, in combination, a plate having latching means mounted adjacent the face plate of the switch, an internally threaded sleeve mounted on the switch key lever, a body member slidably mounted on said sleeve, said body member having a projection for cooperation with said latching means and resilient means mounted in a recess of said body member and between said body member and said sleeve for urging said body member into position with said projection in engagement with said latching means.

5. A latching device for attachment to a key lever switch comprising, in combination, a plate having latching means mounted adjacent the ace plate of the switch, an internally threaded sleeve mounted on the switch key lever, said sleeve having a head, a body member slidably mounted on said sleeve, said body member having means for cooperation with said latching plate and resilient means mounted in a recess of said body member and extending between a shoulder of said body member and the head of said sleeve.

6. A latching device for attachment to a key lever switch'comprising, in combination, a plate having latching means mounted adjacent the face plate of the switch, an internally threaded sleeve mounted on the switch key lever, said sleeve having a head, a tubular body member slidably mounted onsaid sleeve, said body member having means for cooperation with said latching plate and resilient means mounted in a recess of said body member and extending between a shoulder of said body member and the head of said sleeve.

7. A latching device for attachment to a key lever switch comprising, in combination, a plate having latching means mounted adjacent the face plate vof .the switch, an internally threaded sleeve mounted on the switch key lever, said sleeve having a head, a body member Aslidably mounted on said sleeve, said bodymember having means for cooperation `with said latching plate, resilient means mounted in aIecess vof said body member and extending between ,aishoulder of said body member and the head of `said sleeve, and a handle member xed to said'body Amember whereby said body member may bemoved out of engagement with said latching means to permit movement of the key lever to any of its plurality of positions,-

said resilient means returning said body member to latching position-upon release of said handle.

CARL LOMHOLT.

REFERENCES -CITED Thev following vreferences are of record in the file of this patent:

UNITED STATES PATENTS 

